Why Do Floods Happen?

Answer

Floods occur when there is excess water in a river such that its banks burst or if there is too much rainfall. An advantage of floods is that they carry fresh, fertile soil onto land. They could also be disadvantageous when they cause great damage and kill people.

I have no idea if this fits the symptoms you are experiencing or not, but tingling in the hand mainly at night is usually carpal (1°, 2° or 3° digits) or cubital tunnel

http://www.quora.com/My-right-arm-regularly-falls-...

3 Additional Answers

Floods are usually caused by heavy rains that pour a lot of water into rivers together with other waterways, making these natural paths unable to carry all the water. As a result, rising water flows over or smashes the banks to the waterways making the surrounding land to be flooded.

Floods happen when there is so much rain that lakes, ponds and rivers overflow because they fill up too much. Some places are more notorious for flooding and are known as flood zones.

A flood will happen when a area has a lot of rain. The rain breaks apart the soil causing it to erode. With out the soil the water takes over and flooding begins.